My absolutely, №1, can't

My absolutely, №1, can't function without it addon is Card Games (solitaire). I also have Small Screen Renderer. Neither works on newer versions of Firefox. But, fear not. Install Nightly Tester Tools. So far, I've been able to override all compatibility issues without any hoohah. It's designed for folks who like to run the nightlies.

cheers,

gary

If your web page is as clever as you can make it, it's probably too clever for you to debug or maintain.

Most of the problems with

Most of the problems with extensions come from the fact that the install.rdf (iirc) has a maxversion the extension has been tested with and works with. You can change it yourself which in 99% of cases stops the "This addon is not compatible with this version of firefox" - most extension developers are quick to release a new version that works, the only change being a bumped maxversion.

I tend to wait to upgrade

I tend to wait to upgrade until I'm sure that Firebug and Web Dev Tools are compatible, and they generally tend to be fairly rapidly if it's even required, but those two extensions oh plus html validator I couldn't function without now